A solar panel is obviously exposed to the elements in all kinds of weather. In addition such panels are subject to periodic replacement or servicing. Thus it is important that the electrical hookups for them be extremely robust, yet capable of relatively simple connection and disconnection. The electrical connection must also seal tightly and be capable of transmitting the typically low-voltage/high-current electricity produced by the panel with no appreciable loses.
In US 2007/0049125 a plug connector is described for connection of two cables each having an outer jacket and an inner conductor projecting from the respective jacket. The a connector assembly has a tubular plug housing extending along a respective longitudinal axis and formed with a radially inwardly projecting bead forming an axially outwardly directed shoulder and, axially outward from the bead, a radially enlarged-region. A contact plug in the plug housing is formed with a pin projecting axially inward from the respective bead and bearing axially outward on the respective bead, a pair of hooks axially outward of the respective bead and bearing axially inward on the shoulder thereof, whereby the hooks lock the contact plug in the plug housing, and a crimp connector axially outward of the respective bead and gripping the conductor of one of the cables. A seal in the radially enlarged region of the plug housing bears radially inward on the jacket of the one cable whose conductor is gripped by the crimp connector of the contact plug. A tubular socket housing extending along a respective longitudinal axis is formed with a radially inwardly projecting bead forming an axially outwardly directed shoulder and, axially outward from the respective bead, a radially enlarged region. A contact socket in the socket housing is formed with a sleeve projecting axially inward from the respective bead and bearing axially outward on the respective bead, a pair of hooks axially outward of the respective bead and bearing axially inward on the shoulder thereof, whereby the hooks lock the contact socket in the socket housing, and a crimp connector axially outward of the respective bead and gripping the conductor of the other of the cables. Another seal in the radially enlarged region of the socket housing bears radially inward on the jacket of the other cable whose conductor is gripped by the crimp connector of the contact socket. The socket housing and the plug housing are fittable axially together with the cables extending axially oppositely away from each other and with the pin of the contact plug fitted snugly inside the sleeve of the socket housing. One of the housings is formed radially inward of the respective bead with a radially inwardly open groove. A seal ring in the groove radially inwardly engages the other of the housings when the housings are fitted together.
Such a connector has worked fairly well, but requires considerable force to disconnect when the connector has been in use outside for some time, as is common for a connector on a solar panel. The disconnection force is typically longitudinal, so that the worker on the roof must grip the connector in both hands and pull it longitudinally apart, something that can be difficult and dangerous in this work setting, especially when the unit is somewhat frozen together.